美國開徵碳稅正當其時

The case for carbon taxes has long been compelling. With the recent steep fall in oil prices and associated declines in other energy prices it is overwhelming. There is room for debate about the size of the tax and about how the proceeds should be deployed. But there should be no doubt that starting from the current zero tax rate on carbon, increased taxation would be desirable.

碳稅問題長期以來一直備受關注。隨着近期油價暴跌以及其他能源價格的相應下挫，徵收碳稅已是勢在必行。我們有討論碳稅的規模以及稅收如何運用的空間。但毫無疑問的是，以當前碳排放零稅率爲起點而增加的稅收將是可行的。

The core of the case for taxation is the recognition that those who use carbon-based fuels or products do not bear all the costs of their actions. Carbon emissions exacerbate the global climate change problem. In many cases they contribute to local pollution problems which immediately harm human health. Removing fossil fuels from the ground involves both accident risks and environmental challenges. And even with the substantial increases in US oil production we remain a net importer, so increases in consumption raise our dependence on Middle East producers.

碳稅問題的核心是承認那些使用碳基燃料或產品的消費者沒有承擔他們行爲的所有費用。碳排放加劇了全球氣候變化問題。在許多情況下，它們會造成當地的污染問題，這些問題又直接危害人類健康。將化石燃料從地下開採出來既包含事故隱患，也帶來環境挑戰。儘管美國石油產量大幅增加，我們仍是石油淨進口國，所以石油消耗增加提升了我們對中東石油生產國的依賴程度。

When we drive our cars, heat our homes or use fossil fuels in more indirect ways, all of us create these costs without paying for them. It follows that we overuse these fuels. This is not some kind of government planning argument — it is the logic of the market: that which is not paid for is overused. Even if the government had no need or use for revenue, it could make the economy function better by levying carbon taxes and rebating the revenues to society.

當我們駕駛汽車，烘暖房間或通過更間接的方式使用化石燃料時，我們大家產生了這些費用，卻沒有付費。由此可見，我們過度使用了這些燃料。這不是某種政府策劃的結論，而是市場邏輯：不用付費的資源必然被濫用。即使政府不需要或者用不着這部分收入，它也可以通過徵收碳稅、再返還社會的方式使經濟運轉得更良好。

While the recent decline in energy prices is a good thing in that it has on balance raised the incomes of Americans, it does exacerbate the problem of energy overuse. The benefit of imposing carbon taxes is therefore enhanced.

雖然，總的來說，近期能源價格下跌對提高美國民衆收入是一件好事，但這的確加劇了能源過度使用的問題。徵收碳稅的裨益因此也大大增加。

On the other side of the ledger, there has always been the concern that raising carbon taxes would place an unfair burden on some middle- and low-income consumers. Those who drive long distances to work, say, or who have homes that are expensive to heat would be disproportionately burdened. Now these groups have received a windfall from the drop in energy prices so it would be possible to impose substantial carbon taxes without them being burdened relative to where prices stood six months ago. As an example, the price of petrol has fallen by over $1 per gallon. A $25 a tonne tax on carbon that would raise over $1tn during the next decade would lift petrol prices by only about 25 cents.

另一方面，一直以來人們就擔心，提高碳稅會對一些中低收入消費者造成不公平的負擔。比如，那些遠途開車的上班族、或者房屋供暖費用昂貴的人將承受過重的負擔。現在，這些羣體已從能源價格下跌中獲得不少好處，所以徵收相當程度的碳稅而又不增加他們的負擔（相對於6個月前的油價水平）是可行的。例如，汽油價格已下跌逾1美元/加侖。如果每噸二氧化碳排放徵收25美元的碳稅，未來10年的稅收將超過1萬億美元，而汽油價格每加侖僅會提高約25美分。

Some worry that taxing fossil fuels will hurt the competitiveness of US industry and encourage offshoring. In fact a well designed tax would be levied on the carbon content of all imports coming from countries that did not impose their own carbon levies. The US should insist that its tax is compatible with World Trade Organisation rules. It would have the virtue of encouraging countries who wished to avoid the US tax to impose carbon taxes of their own, thereby further supporting efforts to reduce global climate change.

一些人擔心對化石燃料徵稅將損害美國的工業競爭力，並鼓勵產業外移。實際上，通過精心設計，美國將對所有進口商品的碳含量進行徵稅，如果這些產品的出口國沒有對它們課徵碳稅的話。美國應堅持其所徵之稅不違背世界貿易組織(WTO)的規則。這樣美國就可以有資格鼓勵那些希望免受美國課稅的國家徵收本國的碳稅，從而進一步支持減緩全球氣候變化的努力。

A US carbon tax would contribute to efforts to combat climate change in other ways. It would be a hugely important symbolic step ahead of the global climate summit in Paris late this year. It would shift the debate towards harmonised measures to raise the price of carbon use and away from the complex cap-and-trade type systems that in the EU and elsewhere have proven more difficult to operate than expected.

美國徵收碳稅在其他方面也將有助於應對氣候變化的努力。今年底巴黎召開全球氣候變化峯會之前，它將是非常重要的象徵性一步。它將把討論引向通過採取協調一致措施提高碳使用的價格，並使討論避開復雜的“限額與交易”(cap-and-trade)型機制，歐盟及其他地方的經驗已證明這類機制比預期的更難操作。

What size levy is appropriate? Here there is more danger of doing too little than too much. Once the principle of taxation is accepted its level can be adjusted. A tax of $25 a tonne would raise well over 1 per cent of US gross domestic product, or $150bn, each year and seems a reasonable starting point.

碳稅多大規模合適呢？在這一點上，徵得太少比太多反而危險更大。一旦徵稅原則被接受，其標準是可以調整的。如果每噸二氧化碳排放徵稅25美元，每年將帶來大大超過美國國內生產總值(GDP) 1%的收入（1500億美元），這看起來是一個合理的出發點。

How should the proceeds be used? Here too it seems more important to reach consensus on the principle of taxation. My preference would be for the proceeds to be split between investments in infrastructure and pro-work tax credits. An additional $50bn a year in infrastructure spending would be a significant contribution to closing America’s investment gap in that area. The same sum devoted to pro-work tax credits could finance a huge increase in the earned income tax credit, a meaningful reduction in the payroll tax or some combination of the two.

這些收入該如何使用呢？同樣地，在稅收原則上達成共識看起來更加重要。我傾向於將這些收入平分，用於基礎設施投資和促進就業的稅收減免。每年增加500億美元的基礎設施支出將爲美國彌補此領域的投資不足做出巨大貢獻。將同樣數額的碳稅收入用於促進就業的稅收減免，可以大幅增加所得稅減免、顯著降低工資稅或兩者相結合。

Progressives who are concerned about climate change should rally to a carbon tax as the most important step for mobilising against it. Conservatives who believe in the power of markets should favour carbon taxes on market principles. And Americans who want to see their country lead on the energy and climate issues that are crucial to the world this century should want to be in the vanguard on carbon taxes. Now is the time.

關注氣候變化的進步人士應該共同支持把徵收碳稅作爲動員大家應對氣候變化的最重要一步。相信市場力量的保守派人士也應該贊同符合市場規則的碳稅。希望看到自己國家在對當今世界至關重要的能源和氣候問題上發揮領導作用的美國人，應該希望在碳稅問題上發揮先鋒作用。現在正當其時。